My car wont stay running. I have replaced the fuel pump, the fuel pump relay, distributor, pickup coil, module in dist. coil, trottle position censor, new oil pressure switch, new ignition switch with key & chip, new spark plugs, computer so far. The car will crank runs 25 min. until warms up, then starts skipping on #6, if you rev it up it stops skipping then shuts off. sometimes it will start again, sometimes it wont. It never quits firing, and the fuel pressure never drops. This has become a mind boggling problem. Any suggestions for what to check or what the problem could be? I love my little red conv. and desperately want to drive it again.

 

You say it runs up untill it warms up. How's your thermostat? Are you sure it isn't overheating?

 

Then if you say it skips on #6 (I assume you mean 6th cylinder) maybe its an injector problem. Those are my ideas, good luck.

 

check the pick up coil in the distributor. when its cold the connects are tight when it gets hot connection get loose. happen on my old 89 iroc chnged it out ran great

 

If its the 3.1 MPFI then when as few as one injector goes bad that will kill a whole side. (sequential fuel injection). Running for 25 minutes is well past the car warming up.
Have you tried to unplug things like the TPS, EGR, IAC, etc? If there is an item plugged in that is causing it to not run then unplugging that item may lead you to what it is. Have you been able to drive it? Got any service engine light? Codes?